The present invention relates to optical equipment, such as a liquid crystal projector. Especially, the invention is concerned with optical equipment that has a suitable cooling system to cool a light valve arrangement in the optical equipment.
A conventional optical apparatus having a light valve arrangement, as described in Japanese patent Laid-open Publication 8-179424, employs an axial-flow type ventilation device located under the light valve arrangement as a ventilation system so as to prevent the light valve arrangement from reaching a high temperature. In this case, because the flow of air from the ventilation system can be applied to the light valve arrangement directly, the light valve arrangement can be cooled.
Because a ventilation system is provided below the light valve arrangement in the conventional optical equipment, the air is supplied from the base side of the equipment to the ventilation system. Thus, it was necessary to provide a space on the base side of the equipment to reduce the flow resistance of the air that is drawn in from the equipment side. Further, because the height of the optical equipment becomes equal to the height of the ventilation system and a rectifier added to the height of the projection lens or the light valve arrangement, it was difficult to make the equipment thin.
Further, such space was hard to provide in practical use underneath the projection lens (dead space) for this ventilation system, so that it was arranged at a position where it projected from underneath the projection lens, with a result that it wasn't possible to reduce the size of the whole device or effect a reduction of the height measurement.